US11696496B2

US11696496B2 - Organic light-emitting device

Info

Publication number: US11696496B2
Application number: US15/177,360
Authority: US
Inventors: Seulong KIM; Younsun KIM; Dongwoo Shin; Jungsub LEE; Naoyuki Ito; Jino Lim; Hyein Jeong
Original assignee: Samsung Display Co Ltd
Current assignee: Samsung Display Co Ltd
Priority date: 2015-12-22
Filing date: 2016-06-09
Publication date: 2023-07-04
Anticipated expiration: 2036-06-09
Also published as: KR20170075123A; EP3185329A1; US20170179395A1; CN106910831A; CN106910831B; KR102579752B1

Abstract

An organic light-emitting device including a first electrode; a second electrode facing the first electrode; an emission layer between the first electrode and the second electrode; a hole transport region between the first electrode and the emission layer; and an electron transport region between the emission layer and the second electrode, wherein: the emission layer includes a first compound, at least one of the hole transport region and the electron transport region includes a second compound, the first compound is represented by Formula 1A or 1B, and the second compound is represented by Formula 2A or 2B:

Description

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0184084, filed on Dec. 22, 2015, in the Korean Intellectual Property Office, and entitled: “Organic Light-Emitting Device,” is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

Embodiments relate to an organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices that have wide viewing angles, high contrast ratios, short response times, and excellent brightness, driving voltage, and response speed characteristics, compared to devices in the art.

The organic light-emitting device may include a first electrode disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode, which are sequentially disposed on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as holes and electrons, recombine in the emission layer to produce excitons. These excitons transition from an excited state to a ground state, thereby generating light.

SUMMARY

Embodiments are directed to an organic light-emitting device.

One or more embodiments include an organic light-emitting device having a low driving voltage and high efficiency.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

According to one or more embodiments, an organic light-emitting device includes:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode;

a hole transport region between the first electrode and the emission layer; and

an electron transport region between the emission layer and the second electrode,

wherein the emission layer includes a first compound,

at least one selected from the hole transport region and the electron transport region includes a second compound,

the first compound is represented by Formula 1A or 1B, and

the second compound is represented by Formula 2A or 2B:

In Formulae 1A, 1B, 2A, and 2B,

rings A₁to A₃may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀heterocyclic group,

rings A₁to A₃may each be condensed with a spiro-ring in Formulae 1A and 1B,

rings A₂₁, A₂₂, and A₂₃may each independently be a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22],

T₁₁and T₁₂may each independently be carbon or nitrogen, two or more selected from three T₁₁(s) in Formula 2A may be identical to or different from each other, T₁₃may be N or C(R₂₇), T₁₄may be N or C(R₂₈), two or more selected from three T₁₂(s) in Formula 2A may be identical to or different from each other, two T₁₁(s) in Formula 2B may be identical to or different from each other, two T₁₂(s) in Formula 2B may be identical to or different from each other, T₁₁and T₁₂may be connected to each other via a single bond or a double bond, three T₁₁(s) and three T₁₂(s) in Formula 2A may be not all nitrogen and two T₁₁(s), two T₁₂(S), T₁₃, and T₁₄in Formula 2B may be not all nitrogen,

rings A₂₁, A₂₂, and A₂₃may each be condensed (e.g., fused) with a central 7-membered ring in Formulae 2A and 2B, such that they each share a T₁₁and a T₁₂with the central 7-membered ring,

X₁may be a silicon (Si) atom or a carbon (C) atom,

Y₁may be selected from a single bond, N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se,

Y₂may be selected from a single bond, N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), Si(R₁₂)(R₁₄), O, S, and Se,

E₁and E₂may each independently be a nitrogen (N) atom, or may each independently be a carbon (C) atom substituted with *-(L₄)_a4-(R₄)_b4,

X₂₁may be selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N[(L₂₁)_a21-(R₂₁)_b21],

L₁to L₄, L₁₁, L₁₂, L₂₁, and L₂₂may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

a1 to a4, a11, a12, a21, and a22 may each independently be an integer selected from 0 to 5,

R₁to R₄, R₁₁to R₁₄, R₂₁to R₂₄, R₂₇, and R₂₈may each independently be selected from hydrogen, deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

R₁₁and R₁₃may be optionally connected to each other to form a saturated or unsaturated ring,

R₁₂and R₁₄may be optionally connected to each other to form a saturated or unsaturated ring,

b1 to b4, b11, b12, b21, and b22 may each independently be an integer selected from 1 to 3,

c1 and c2 may each independently be an integer selected from 0 to 8, and c3 and c4 may each independently be an integer selected from 0 to 4, and

at least one substituent selected from the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀alkoxy group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀alkoxy group;

a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group;

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁to Q₃, Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryl group substituted with a C₁-C₆₀alkyl group, a C₆-C₆₀aryl group substituted with a C₆-C₆₀aryl group, a terphenyl group, a C₁-C₆₀heteroaryl group, a C₁-C₆₀heteroaryl group substituted with a C₁-C₆₀alkyl group, a C₁-C₆₀heteroaryl group substituted with a C₆-C₆₀aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will be apparent to those of skill in the art by describing in detail exemplary embodiments with reference to the attached drawings in which:

FIGS. 1 to 5 illustrate schematic views of organic light-emitting devices according to various embodiments.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that when a layer or element is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Further, it will be understood that when a layer is referred to as being “under” another layer, it can be directly under, and one or more intervening layers may also be present. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.

An organic light-emitting device according to an embodiment may include a first electrode, a second electrode facing the first electrode, an emission layer between the first electrode and the second electrode, a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode, wherein the emission layer may include a first compound and at least one selected from the hole transport region and the electron transport region may include a second compound.

The first compound may be represented by Formula 1A or 1B, and the second compound may be represented by Formula 2A or 2B:

In Formulae 1A and 1B,

rings A₁to A₃may each independently be selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀heterocyclic group, and

rings A₁to A₃may each be condensed with a spiro-ring in Formulae 1A and 1B.

For example, rings A₁to A₃in Formulae 1A and 1B may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an indene group, an indenopyridine group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyrrole group, an imidazole group, a quinoline group, an isoquinoline group, a quinazoline group, a phenanthroline group, a phenanthridine group, a furan group, a thiophene group, an indole group, an indolocarbazole group, a benzofuran group, a benzofurocarbazole group, a benzofuropyrimidine group, a benzothiophene group, a benzoxazole group, a benzothiazole group, a benzoimidazole group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a pyridoindole group, a dipyridofuran group, a dipyridothiophene group, a pyrimidobenzofuran group, a dipyridopyrrole group, and a pyrimidobenzothiophene group.

In various embodiments, ring A₁in Formulae 1A and 1B may be selected from a benzene group, a naphthalene group, a pyridine group, a dibenzofuran group, and a pyrimidine group, and

rings A₂and A₃may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an indene group, an indenopyridine group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyrrole group, an imidazole group, a quinoline group, an isoquinoline group, a quinazoline group, a phenanthroline group, a phenanthridine group, a furan group, a thiophene group, an indole group, an indolocarbazole group, a benzofuran group, a benzofurocarbazole group, a benzofuropyrimidine group, a benzothiophene group, a benzoxazole group, a benzothiazole group, a benzoimidazole group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a pyridoindole group, a dipyridofuran group, a dipyridothiophene group, a pyrimidobenzofuran group, a dipyridopyrrole group, and a pyrimidobenzothiophene group.

Rings A₂₁, A₂₂, and A₂₃in Formulae 2A and 2B may each independently be a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22]. L₂₂, a22, R₂₂, and b22 are the same as described below.

T₁₁and T₁₂in Formulae 2A and 2B may each independently be carbon or nitrogen, two or more selected from three T₁₁(s) in Formula 2A may be identical to or different from each other, T₁₃may be N or C(R₂₇), T₁₄may be N or C(R₂₈), two or more selected from three T₁₂(s) in Formula 2A may be identical to or different from each other, two T₁₁(s) in Formula 2B may be identical to or different from each other, two T₁₂(S) in Formula 2B may be identical to or different from each other, T₁₁and T₁₂may be connected to each other via a single bond or a double bond, three T₁₁(s) and three T₁₂(s) in Formula 2A may be not all nitrogen and two T₁₁(s), two T₁₂(s), T₁₃, and T₁₄in Formula 2B may be not all nitrogen, and rings A₂₁, A₂₂, and A₂₃may each be condensed (e.g., fused) with a central 7-membered ring in Formulae 2A and 2B, such that they each share a T₁₁and a T₁₂with the central 7-membered ring.

*-[(L₂₂)_a22-(R₂₂)_b22] substituted in ring A₂₁, *-[(L₂₂)_a22-(R₂₂)_b22] substituted in ring A₂₂, and *-[(L₂₂)_a22-(R₂₂)_b22] substituted in ring A₂₃may be identical to or different from one another.

In addition, when the number of *-[(L₂₂)_a22-(R₂₂)_b22](s) substituted in ring A₂₁is two or more, two or more *-[(L₂₂)_a22-(R₂₂)_b22](s) may be identical to or different from each other, when the number of *-[(L₂₂)_a22-(R₂₂)_b22](s) substituted in ring A₂₂is two or more, two or more *-[(L₂₂)_a22-(R₂₂)_b22](s) may be identical to or different from each other, and when the number of *-[(L₂₂)_a22-(R₂₂)_b22] (s) substituted in ring A₂₃is two or more, two or more *-[(L₂₂)_a22-(R₂₂)_b22](s) may be identical to or different from each other.

In various embodiments, rings A₂₁, A₂₂, and A₂₃in Formulae 2A and 2B may each independently be selected from a benzene group, a naphthalene group, an anthracene group, an indene group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a pyrrole group, a pyrazole group, an imidazole group, an oxazole group, a thiazole group, a cyclopentadiene group, a silole group, a selenophene group, a furan group, a thiophene group, an indole group, a benzoimidazole group, a benzoxazole group, a benzothiazole group, an indene group, a benzosilole group, a benzoselenophene group, a benzofuran group, a benzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene group, a pyrrolopyridine group, a cyclopentapyridine group, a silolopyridine group, a selenophenopyridine group, a furopyridine group, a thienopyridine group, a pyrrolopyrimidine group, a cyclopentapyrimidine group, a silolopyrimidine group, a selenophenopyrimidine group, a furopyrimidine group, a thienopyrimidine group, a pyrrolopyrazine group, a cyclopentapyrazine group, a silolopyrazine group, a selenophenopyrazine group, a furopyrazine group, a thienopyrazine group, a naphthopyrrole group, a cyclopentanaphthalene group, a naphthosilole group, a naphthoselenothiophene group, a naphthofuran group, a naphthothiophene group, a pyrroloquinoline group, a cyclopentaquinoline group, a siloloquinoline group, a selenophenoquinoline group, a furoquinoline group, a thienoquinoline group, a pyrroloisoquinoline group, a cyclopentaisoquinoline group, a siloloisoquinoline group, a selenophenoisoquinoline group, a furoisoquinoline group, a thienoisoquinoline group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene group, an indenoquinoline group, an indenoisoquinoline group, an indenoquinoxaline group, a phenanthroline group, and a naphthoindole group, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22].

In various embodiments, in the second compound represented by Formulae 2A and 2B, a case where rings A₂₁, A₂₂, and A₂₃are all a benzene group substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22] may be excluded.

In various embodiments, rings A₂₁, A₂₂, and A₂₃in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 2-1 to 2-36, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22]:

In Formulae 2-1 to 2-36,

T₁₁and T₁₂are the same as described above,

X₂₂and X₂₃may each independently be selected from O, S, Se, a moiety including C, a moiety including N, and a moiety including Si, and

T₂₁to T₂₈may each independently be selected from N and a moiety including C.

When both X₂₂and X₂₃are included in rings A₂₁to A₂₃, X₂₂and X₂₃may be identical to or different from each other.

For example, in Formulae 2-1 to 2-36, X₂₂and X₂₃may each independently be O, S, Se, C(R₂₅)(R₂₆), N-[(L₂₂)_a22-(R₂₂)_b22], or Si(R₂₅)(R₂₆), and T₂₁to T₂₈may each independently be N or C-[(L₂₂)_a22-(R₂₂)_b22]. R₂₅and R₂₆may each independently be selected from groups represented by *-[(L₂₂)_a22-(R₂₂)_b22)] as described herein.

In various embodiments, rings A₂₁, A₂₂, and A₂₃in Formulae 2A and 2B may each independently be selected from groups represented by Formulae 2-101 to 2-229:

In Formulae 2-101 to 2-229,

T₁₁and T₁₂are the same as described above,

X₂₂and X₂₃are the same as described above, and

R₃₁to R₃₈may each independently be selected from substituents represented by *-[(L₂₂)_a22-(R₂₂)_b22] as described herein.

In R₃₁to R₃₈, when the number of *-[(L₂₂)_a22-(R₂₂)_b22](S) is two or more, two or more *-[(L₂₂)_a22-(R₂₂)_b22](s) may be identical to or different from each other.

For example, in Formulae 2A to 2B, a case where rings A₂₁, A₂₂, and A₂₃are all represented by Formula 2-104 may be excluded.

In various embodiments, the second compound may be represented by one selected from Formulae 2-201A to 2-269A, and rings A₂₁, A₂₂, and A₂₃in Formulae 2-201A to 2-269A may each be selected from Formulae shown in Table 1.

TABLE 1

	Formula
	No. of ring	Formula No. of ring	Formula No. of ring
Formula No.	A₂₁	A₂₂	A₂₃

2-201A	2-2	2-4	2-4
2-202A	2-4	2-4	2-1
2-203A	2-4	2-4	2-2
2-204A	2-4	2-4	2-3
2-205A	2-4	2-1	2-4
2-206A	2-4	2-2	2-4
2-207A	2-4	2-4	2-10
2-208A	2-11	2-4	2-4
2-209A	2-4	2-4	2-11
2-210A	2-4	2-10	2-4
2-211A	2-4	2-4	2-8
2-212A	2-4	2-9	2-4
2-213A	2-4	2-4	2-14
2-214A	2-17	2-4	2-4
2-215A	2-4	2-4	2-15
2-216A	2-13	2-4	2-4
2-217A	2-4	2-4	2-16
2-218A	2-4	2-4	2-13
2-219A	2-16	2-4	2-4
2-220A	2-4	2-4	2-12
2-221A	2-4	2-4	2-17
2-222A	2-4	2-16	2-4
2-223A	2-4	2-15	2-4
2-224A	2-4	2-14	2-4
2-225A	2-4	2-17	2-4
2-226A	2-19	2-4	2-4
2-227A	2-22	2-4	2-4
2-228A	2-18	2-4	2-4
2-229A	2-23	2-4	2-4
2-230A	2-21	2-4	2-4
2-231A	2-20	2-4	2-4
2-232A	2-4	2-23	2-4
2-233A	2-4	2-18	2-4
2-234A	2-4	2-21	2-4
2-235A	2-4	2-19	2-4
2-236A	2-5	2-2	2-4
2-237A	2-5	2-1	2-4
2-238A	2-2	2-2	2-4
2-239A	2-4	2-23	2-1
2-240A	2-6	2-10	2-4
2-241A	2-4	2-4	2-29
2-242A	2-7	2-4	2-10
2-243A	2-11	2-4	2-10
2-244A	2-4	2-10	2-6
2-245A	2-11	2-11	2-4
2-246A	2-11	2-11	2-5
2-247A	2-11	2-11	2-10
2-248A	2-7	2-9	2-4
2-249A	2-4	2-4	2-25
2-250A	2-11	2-15	2-4
2-251A	2-18	2-28	2-4
2-252A	2-23	2-10	2-4
2-253A	2-4	2-27	2-4
2-254A	2-6	2-18	2-4
2-255A	2-4	2-23	2-5
2-256A	2-23	2-4	2-14
2-257A	2-17	2-4	2-14
2-258A	2-14	2-4	2-12
2-259A	2-17	2-4	2-12
2-260A	2-14	2-16	2-2
2-261A	2-17	2-5	2-14
2-262A	2-17	2-13	2-17
2-263A	2-17	2-14	2-12
2-264A	2-17	2-12	2-12
2-265A	2-5	2-1	2-18
2-266A	2-4	2-29	2-4
2-267A	2-4	2-31	2-4
2-268A	2-4	2-33	2-4
2-269A	2-4	2-35	2-4

In various embodiments, the second compound may be represented by one selected from Formulae 2-201B to 2-215B, and rings A₂₁and A₂₃in Formulae 2-201B to 2-215B may each be selected from Formulae shown in Table 2.

TABLE 2

	Formula
	No. of ring	Formula No. of ring	Formula No. of ring
Formula No.	A₂₁	A₂₂	A₂₃

2-201B	2-4	—	2-19
2-202B	2-4	—	2-22
2-203B	2-4	—	2-18
2-204B	2-4	—	2-23
2-205B	2-4	—	2-21
2-206B	2-4	—	2-20
2-207B	2-5	—	2-23
2-208B	2-7	—	2-23
2-209B	2-4	—	2-26
2-210B	2-7	—	2-22
2-211B	2-13	—	2-16
2-212B	2-5	—	2-19
2-213B	2-7	—	2-20
2-214B	2-19	—	2-18
2-215B	2-18	—	2-18

In various embodiments, the second compound may be represented by one selected from Formulae 2-301A to 2-421A, and rings A₂₁, A₂₂, and A₂₃in Formulae 2-301A to 2-419A and 2-421A to 2-431A may each be selected from Formulae shown in Table 3.

TABLE 3

	Formula
	No. of ring	Formula No. of ring	Formula No. of ring
Formula No.	A₂₁	A₂₂	A₂₃

2-301A	2-104	2-147	2-104
2-302A	2-102	2-104	2-104
2-303A	2-104	2-104	2-101
2-304A	2-104	2-104	2-102
2-305A	2-104	2-104	2-103
2-306A	2-104	2-101	2-104
2-307A	2-104	2-102	2-104
2-308A	2-104	2-104	2-147
2-309A	2-157	2-104	2-104
2-310A	2-104	2-104	2-157
2-311A	2-104	2-147	2-107
2-312A	2-104	2-149	2-104
2-313A	2-104	2-156	2-104
2-314A	2-107	2-147	2-106
2-315A	2-104	2-151	2-104
2-316A	2-104	2-147	2-106
2-317A	2-104	2-148	2-104
2-318A	2-104	2-150	2-104
2-319A	2-106	2-147	2-104
2-320A	2-104	2-106	2-147
2-321A	2-157	2-107	2-104
2-322A	2-106	2-104	2-147
2-323A	2-104	2-107	2-147
2-324A	2-107	2-104	2-147
2-325A	2-104	2-104	2-160
2-326A	2-104	2-111	2-157
2-327A	2-108	2-104	2-158
2-328A	2-111	2-104	2-157
2-329A	2-107	2-147	2-104
2-330A	2-104	2-104	2-135
2-331A	2-104	2-141	2-104
2-332A	2-104	2-142	2-104
2-333A	2-107	2-104	2-135
2-334A	2-104	2-111	2-135
2-335A	2-104	2-143	2-104
2-336A	2-106	2-142	2-104
2-337A	2-107	2-142	2-106
2-338A	2-104	2-104	2-169
2-339A	2-184	2-104	2-104
2-340A	2-104	2-104	2-182
2-341A	2-168	2-104	2-104
2-342A	2-104	2-104	2-183
2-343A	2-104	2-104	2-168
2-344A	2-183	2-104	2-104
2-345A	2-104	2-104	2-167
2-346A	2-104	2-104	2-184
2-347A	2-104	2-183	2-104
2-348A	2-104	2-182	2-104
2-349A	2-104	2-169	2-104
2-350A	2-104	2-184	2-104
2-351A	2-107	2-104	2-179
2-352A	2-111	2-104	2-169
2-353A	2-104	2-111	2-182
2-354A	2-106	2-104	2-185
2-355A	2-171	2-104	2-104
2-356A	2-104	2-104	2-115
2-357A	2-104	2-104	2-178
2-358A	2-104	2-106	2-167
2-359A	2-108	2-105	2-167
2-360A	2-105	2-104	2-167
2-361A	2-112	2-104	2-184
2-362A	2-104	2-192	2-104
2-363A	2-107	2-182	2-106
2-364A	2-104	2-169	2-105
2-365A	2-105	2-184	2-104
2-366A	2-105	2-169	2-105
2-367A	2-198	2-104	2-104
2-368A	2-201	2-104	2-104
2-369A	2-197	2-104	2-104
2-370A	2-202	2-104	2-104
2-371A	2-200	2-104	2-104
2-372A	2-199	2-104	2-104
2-373A	2-104	2-202	2-104
2-374A	2-104	2-197	2-104
2-375A	2-104	2-200	2-104
2-376A	2-104	2-198	2-104
2-377A	2-209	2-104	2-104
2-378A	2-207	2-104	2-104
2-379A	2-200	2-106	2-104
2-380A	2-104	2-208	2-104
2-381A	2-105	2-198	2-108
2-382A	2-202	2-102	2-104
2-383A	2-202	2-101	2-106
2-384A	2-102	2-102	2-107
2-385A	2-104	2-202	2-101
2-386A	2-123	2-147	2-104
2-387A	2-104	2-104	2-218
2-388A	2-116	2-104	2-147
2-389A	2-157	2-104	2-147
2-390A	2-107	2-147	2-115
2-391A	2-157	2-157	2-104
2-392A	2-157	2-157	2-114
2-393A	2-157	2-157	2-147
2-394A	2-116	2-147	2-104
2-395A	2-104	2-104	2-210
2-396A	2-157	2-182	2-104
2-397A	2-197	2-213	2-104
2-398A	2-202	2-167	2-104
2-399A	2-104	2-216	2-104
2-400A	2-124	2-197	2-104
2-401A	2-104	2-202	2-114
2-402A	2-168	2-104	2-169
2-403A	2-184	2-104	2-169
2-404A	2-169	2-104	2-167
2-405A	2-184	2-106	2-167
2-406A	2-169	2-183	2-102
2-407A	2-184	2-114	2-169
2-408A	2-184	2-168	2-184
2-409A	2-184	2-104	2-167
2-410A	2-184	2-167	2-167
2-411A	2-114	2-101	2-197
2-412A	2-104	2-149	2-104
2-413A	2-106	2-104	2-147
2-414A	2-104	2-104	2-168
2-415A	2-200	2-106	2-104
2-416A	2-104	2-104	2-183
2-417A	2-104	2-104	2-101
2-418A	2-105	2-169	2-105
2-419A	2-104	2-147	2-107
2-421A	2-104	2-218	2-104
2-422A	2-104	2-226	2-104
2-423A	2-104	2-222	2-104
2-424A	2-104	2-228	2-104
2-425A	2-104	2-151	2-104
2-426A	2-106	2-147	2-107
2-427A	2-104	2-147	2-106
2-428A	2-107	2-150	2-104
2-429A	2-104	2-143	2-104
2-430A	2-107	2-142	2-106
2-431A	2-104	2-142	2-104

In various embodiments, the second compound may be represented by one selected from Formulae 2-301B to 2-320B, and rings A₂₁and A₂₃in Formulae 2-301B to 2-320B may each be selected from Formulae shown in Table 4.

TABLE 4

	Formula
	No. of ring	Formula No. of ring	Formula No. of ring
Formula No.	A₂₁	A₂₂	A₂₃

2-301B	2-104	—	2-198
2-302B	2-104	—	2-201
2-303B	2-104	—	2-197
2-304B	2-104	—	2-202
2-305B	2-104	—	2-200
2-306B	2-104	—	2-199
2-307B	2-104	—	2-203
2-308B	2-104	—	2-204
2-309B	2-106	—	2-205
2-310B	2-104	—	2-206
2-311B	2-112	—	2-199
2-312B	2-114	—	2-202
2-313B	2-116	—	2-202
2-314B	2-104	—	2-214
2-315B	2-130	—	2-201
2-316B	2-168	—	2-183
2-317B	2-114	—	2-198
2-318B	2-116	—	2-199
2-319B	2-198	—	2-197
2-320B	2-197	—	2-197

X₁in Formulae 1A and 1B may be silicon (Si) or carbon (C).

For example, X₁in Formulae 1A and 1B may be C.

In Formulae 1A and 1B,

Y₁may be selected from a single bond, N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se, and

Y₂may be selected from a single bond, N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), Si(R₁₂)(R₁₄), O, S, and Se.

For example, in Formulae 1A and 1B,

Y₁and Y₂may be a single bond,

Y₁may be a single bond, and Y₂may be selected from N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), Si(R₁₂)(R₁₄), O, S, and Se, or

Y₁may be selected from N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se, and Y₂may be a single bond.

In various embodiments, in Formulae 1A and 1B,

Y₁and Y₂may be a single bond,

Y₁may be a single bond, and Y₂may be selected from N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), O, and S, or

Y₁may be selected from N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), O, and S, and Y₂may be a single bond.

For example, in Formula 1B,

Y₁may be selected from a single bond, N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₅), O, and S.

E₁and E₂in Formulae 1A and 1B may each independently be a nitrogen (N) atom, or may each independently be a carbon (C) atom substituted with *-(L₄)_a4-(R₄)_b4.

When E₁and E₂in Formulae 1A and 1B are a carbon (C) atom substituted with *-(L₄)_a4-(R₄)_b4, two *-(L₄)_a4-(R₄)_b4(s) may be identical to or different from each other.

X₂₁in Formulae 2A and 2B may be selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_a21-(R₂₁)_b21].

In various embodiments, X₂₁in Formulae 2A and 2B may be N[(L₂₁)_a21-(R₂₁)_b21].

In various embodiments, X₂₁in Formulae 2A and 2B may be O, S, Se, C(R₂₃)(R₂₄), or Si(R₂₃)(R₂₄), and

at least one selected from rings A₂₁, A₂₂, and A₂₃in Formula 2A and at least one selected from rings A₂₁and A₂₃in Formula 2B may each independently be selected from groups represented by Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36, and X₂₂or X₂₃in Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36 may be N-[(L₂₂)_a22-(R₂₂)_b22].

In various embodiments, X₂₁in Formulae 2A and 2B may be O, S, Se, C(R₂₃)(R₂₄), or Si(R₂₃)(R₂₄),

at least one selected from rings A₂₁, A₂₂, and A₂₃in Formula 2A and at least one selected from rings A₂₁and A₂₃in Formula 2B may each independently be selected from groups represented by Formulae 2-101 to 2-103, 2-147 to 2-211, 2-214 to 2-219, and 2-226 to 2-229, and X₂₂or X₂₃in Formulae 2-101 to 2-103, 2-147 to 2-211, 2-214 to 2-219, and 2-226 to 2-229 may be N-[(L₂₂)_a22-(R₂₂)_b22].

In Formulae 2A and 2B, X₂₁may be O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), or N-[(L₂₁)_a21-(R₂₁)_b21], and X₂₂and X₂₃may each independently be O, S, Se, C(R₂₅)(R₂₆), Si(R₂₅)(R₂₆), or N-[(L₂₂)_a22-(R₂₂)_b22]. L₂₁, L₂₂, a21, a22, R₂₁to R₂₆, b21, and b22 are the same as described below.

L₁to L₄, L₁₁, L₁₂, L₂₁, and L₂₂in Formulae 1A, 1B, 2A, and 2B may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group.

For example, in Formulae 1A, 1B, 2A, and 2B,

L₁to L₄, L₁₁, L₁₂, L₂₁, and L₂₂may each independently be selected from

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁to Q₃₃may each independently be selected from

a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, and a phenyl group.

In various embodiments, L₁to L₄, L₁₁, L₁₂, L₂₁, and L₂₂in Formulae 1A, 1B, 2A, and 2B may each independently be selected from groups represented by Formulae 3-1 to 3-100:

In Formulae 3-1 to 3-100,

Y₁may be O, S, C(Z₃)(Z₄), N(Z₅), or Si(Z₆)(Z₇),

Z₁to Z₇may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

Q₃₁to Q₃₃may each independently be selected from

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, and a quinazolinyl group, each substituted with at least one selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, and a phenyl group,

d2 may be an integer selected from 0 to 2,

d3 may be an integer selected from 0 to 3,

d4 may be an integer selected from 0 to 4,

d5 may be an integer selected from 0 to 5,

d6 may be an integer selected from 0 to 6,

d8 may be an integer selected from 0 to 8, and

* and *′ indicate a binding site to a neighboring atom.

In Formulae 1A, 1B, 2A, and 2B, a1 to a4, a11, a12, a21, and a22 indicate the number of L₁(s), the number of L₂(s), the number of L₃(s), the number of L₄(s), the number of L₁₁(s), the number of L₁₂(s), the number of L₂₁(s), and the number of L₂₂(s), respectively. In Formulae 1A, 1B, 2A, and 2B, a1 to a4, a11, a12, a21, and a22 may each independently be an integer selected from 0 to 5. When a1 is two or more, two or more L₁(s) may be identical to or different from each other, when a2 is two or more, two or more L₂(s) may be identical to or different from each other, when a3 is two or more, two or more L₃(s) may be identical to or different from each other, when a4 is two or more, two or more L₄(s) may be identical to or different from each other, when a11 is two or more, two or more L₁(s) may be identical to or different from each other, when a12 is two or more, two or more L₁₂(s) may be identical to or different from each other, when a21 is two or more, two or more L₂₁(s) may be identical to or different from each other, and when a22 is two or more, two or more L₂₂(s) may be identical to or different from each other.

When a1 is zero, *-(L₁)_a1-*′ may be a single bond, when a2 is zero, *-(L₂)_a2-*′ may be a single bond, when a3 is zero, *-(L₃)_a3-*′ may be a single bond, when a4 is zero, *-(L₄)_a4-*′ may be a single bond, when a11 is zero, *-(L₁)_a11-*′ may be a single bond, when a12 is zero, *-(L₁₂)_a12-*′ may be a single bond, when a21 is zero, *-(L₂₁)_a21-*′ may be a single bond, and when a22 is a zero, *-(L₂₂)_a22-*′ may be a single bond.

In various embodiments, a1 to a4, a11, a12, a21, and a22 in Formulae 1A, 1B, 2A, and 2B may each independently be an integer selected from 0 to 3.

In Formulae 1A, 1B, 2A, and 2B,

R₁to R₄, R₁₁to R₁₄, R₂₁to R₂₄, R₂₇, and R₂₈may each independently be selected from hydrogen, deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q), and —P(═O)(Q₁)(Q₂).

In an implementation, R₁₁and R₁₃may be separate or may be connected to each other to form a saturated or unsaturated ring.

In an implementation, R₁₂and R₁₄may be separate or may be connected to each other to form a saturated or unsaturated ring.

For example, in Formulae 1A, 1B, 2A, and 2B,

R₁to R₄, R₁₁to R₁₄, R₂₁to R₂₄, R₂₇, and R₂₈may each independently be selected from

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, and a C₁-C₂₀alkoxy group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group; and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁to Q₃and Q₃₁to Q₃₃may each independently be selected from

In various embodiments,

in Formulae 1A, 1B, 2A, and 2B,

groups represented by Formulae 5-1 to 5-45 and Formulae 6-1 to 6-124; and

—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₁):

In Formulae 5-1 to 5-45 and 6-1 to 6-124,

Y₃₁and Y₃₂may each independently be O, S, C(Z₃₃)(Z₃₄), N(Z₃₅), or Si(Z₃₆)(Z₃₇),

Y₄₁may be N or C(Z₄₁), Y₄₂may be N or C(Z₄₂), Y₄₃may be N or C(Z₄₃), Y₄₄may be N or C(Z₄₄), Y₅₁may be N or C(Z₅₁), Y₅₂may be N or C(Z₅₂), Y₅₃may be N or C(Z₅₃), Y₅₄may be N or C(Z₅₄), at least one selected from Y₄₁to Y₄₃and Y₅₁to Y₅₄in Formulae 5-118 to 5-121 may be N, and at least one selected from Y₄₁to Y₄₄and Ys₅₁to Y₅₄in Formula 5-122 may be N,

Z₃₁to Z₃₇, Z₄₁to Z₄₄, and Z₅₁to Z₅₄may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₁to Q₃and Q₃₁to Q₃₃may each independently be selected from

e3 may be an integer selected from 0 to 3,

e2 may be an integer selected from 0 to 2,

e4 may be an integer selected from 0 to 4,

e5 may be an integer selected from 0 to 5,

e6 may be an integer selected from 0 to 6,

e7 may be an integer selected from 0 to 7,

e9 may be an integer selected from 0 to 9, and

* indicates a binding site to a neighboring atom.

In various embodiments,

in Formulae 1A to 1E, 2A, and 2B,

R₁to R₄, R₂₂to R₂₄, R₂₇, and R₂₈may each independently be selected from

groups represented by Formulae 9-1 to 9-100 and 10-1 to 10-121; and

—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), and

R₁₁to R₁₄and R₂₁may each independently be selected from groups represented by Formulae 9-1 to 9-100 and 10-1 to 10-121; and

—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂):

In Formulae 9-1 to 9-100 and 10-1 to 10-121, Ph refers to a phenyl group, and * indicates a binding site to a neighboring atom.

In Formulae 1A, 1B, 2A, and 2B, b to b4, b11, b12, b21, and b22 indicate the number of R₁(s), the number of R₂(s), the number of R₃(s), the number of R₄(s), the number of R₁₁(s), the number of R₁₂(s), the number of R₂₁(s), and the number of R₂₂(s), respectively. b1 to b4, b11, b12, b21, and b22 may each independently be an integer selected from 1 to 3.

When b1 is two or more, two or more R₁(s) may be identical to or different from each other, when b2 is two or more, two or more R₂(s) may be identical to or different from each other, when b3 is two or more, two or more R₃(s) may be identical to or different from each other, when b4 is two or more, two or more R₄(s) may be identical to or different from each other, when b11 is two or more, two or more R₁₁(s) may be identical to or different from each other, when b12 is two or more, two or more R₁₂(s) may be identical to or different from each other, when b21 is two or more, two or more R₂₁(s) may be identical to or different from each other, and when b22 is two or more, two or more R₂₂(s) may be identical to or different from each other.

In Formulae 1A, 1B, 2A, and 2B, c1 to c4 indicate the number of *-[(L₁)_a1-(R₁)_b1](s), the number of *-[(L₂)_a2-(R₂)_b2](s), the number of *-[(L₃)_a3-(R₃)_b3](s), and the number of *-[(L₄)_a4-(R₄)_b4](s), respectively. c1 and c2 may each independently be an integer selected from 0 to 8, and c3 and c4 may each independently be an integer selected from 0 to 4.

When c1 is two or more, two or more *-[(L₁)_a1-(R₁)_b1](s) may be identical to or different from each other, when c2 is two or more, two or more *-[(L₂)_a2-(R₂)_b2](S) may be identical to or different from each other, when c3 is two or more, two or more *-[(L₃)_a3-(R₃)_b3](s) may be identical to or different from each other, and when c4 is two or more, two or more *-[(L₄)_a4-(R₄)_b4](s) may be identical to or different from each other.

For example, in Formulae 1A, 1B, 2A, and 2B,

the sum of c1 to c4 may be 1, 2, or 3.

In various embodiments, the first compound may be represented by one selected from Formulae 1-1 to 1-3:

In Formulae 1-1 to 1-3,

rings A₁to A₃, X₁, Y₁, E₁, E₂, L₁to L₄, a1 to a4, R₁to R₄, b1 to b4, c1, c2, and c4 are the same as described above,

c2 may be an integer selected from 0 to 6,

Y₁may be selected from N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se, and

L₁₁, a11, R₁₁, R₁₃, and b11 are the same as described above.

For example, in Formulae 1-1 to 1-3,

ring A₁may be selected from a benzene group, a naphthalene group, a pyridine group, a dibenzofuran group, and a pyrimidine group,

rings A₂and A₃may each independently be selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an indene group, an indenopyridine group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyrrole group, an imidazole group, a quinoline group, an isoquinoline group, a quinazoline group, a phenanthroline group, a phenanthridine group, a furan group, a thiophene group, an indole group, an indolocarbazole group, a benzofuran group, a benzofurocarbazole group, a benzofuropyrimidine group, a benzothiophene group, a benzoxazole group, a benzothiazole group, a benzoimidazole group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a pyridoindole group, a dipyridofuran group, a dipyridothiophene group, a pyrimidobenzofuran group, a dipyridopyrrole group, and a pyrimidobenzothiophene group, and

R₁to R₄may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂).

In various embodiments, the first compound may be selected from Compounds 1-1 to 1-160:

In various embodiments, the second compound may be selected from Compounds 2-1a to 2-172a and 2-1 to 2-262:

Any combinations of rings A₁to A₃, X₁, E₁, E₂, Y₁, Y₂, L₁to L₄, a1 to a4, R₁to R₄, b1 to b4, and c1 to c4 in Formulae 1A and 1B may be applicable within the scope described herein.

Any combinations of ring A₂₁, ring A₂₂, ring A₂₃, X₂₁, and T₁₁to T₁₄in Formulae 2A and 2B may be applicable within the scope described herein.

Any combinations of *-[(L₂₂)_a22-(R₂₂)_b22], C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N-[(L₂₁)_a21-(R₂₁)_b21] may be applicable within the scope of L₂₁, L₂₂, a21, a22, R₂₁to R₂₄, b21, and b22 described herein.

The emission layer of the organic light-emitting device according to an embodiment may include the first compound and at least one selected from the hole transport region and the electron transport region may include the second compound, and adjustment of a balance of electrons and/or holes injected or transported into the emission layer may be facilitated, thereby reducing the possibility of and/or preventing a leakage current from occurring. Accordingly, the organic light-emitting device according to an embodiment may have low driving voltage and high efficiency characteristics.

In various embodiment, triplet energy of the second compound may be about 2.2 eV or more. For example, the triplet energy of the second compound may be about 2.3 eV or more, or may be about 2.4 eV or more.

When the triplet energy of the second compound is within these ranges, the emission efficiency of a fluorescent organic light-emitting device may be be improved due to triplet-triplet fusion (TTF). In a phosphorescent organic light-emitting device, it is possible to prevent a reduction in efficiency of an organic light-emitting device by blocking transition of triplet excitons formed in an emission layer.

For example, the emission layer may include a first host and a second host, and the first host may include the first compound.

In various embodiments, the hole transport region may include an emission auxiliary layer, the emission auxiliary layer may directly contact the emission layer, and the second compound may be included in the emission auxiliary layer.

In various embodiments, the electron transport region may include a buffer layer, the buffer layer may directly contact the emission layer, and the second compound may be included in the buffer layer.

When both the hole transport region and the electron transport region in the organic light-emitting device include the second compound described above, the second compound included in the hole transport region and the second compound included in the electron transport region may be identical to or different from each other.

The emission layer may include a dopant, and the dopant may be an organometallic complex.

[Description of FIG. 1 ]

FIG. 1 illustrates a schematic view of an organic light-emitting device 10 according to an embodiment. The organic light-emitting device 10 may include a first electrode 110, an organic layer 150, and a second electrode 190.

Hereinafter, the structure of the organic light-emitting device 10 according to an embodiment and a method of manufacturing the organic light-emitting device 10 will be described in connection with FIG. 1 .

[First electrode 110]

In FIG. 1 , a substrate may be additionally disposed under the first electrode 110 or above the second electrode 190. The substrate may be a glass substrate or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water-resistance.

The first electrode 110 may be formed by depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, the material for forming the first electrode 110 may be selected from materials with a high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissible electrode, a material for forming the first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinations thereof. When the first electrode 110 is a semi-transmissive electrode or a reflective electrode, as a material for forming the first electrode 110, magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), or any combination thereof may be used.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO.

[Organic layer 150]

The organic layer 150 is disposed on the first electrode 110. The organic layer 150 may include an emission layer.

The organic layer 150 may include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 190.

[Hole Transport Region in Organic Layer 150]

The hole transport region may have, e.g., i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

For example, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having a structure of hole injection layer/hole transport layer, hole injection layer/hole transport layer/emission auxiliary layer, hole injection layer/emission auxiliary layer, hole transport layer/emission auxiliary layer or hole injection layer/hole transport layer/electron blocking layer, wherein, in each of these structures, constituting layers are sequentially stacked from the first electrode 110 in this stated order.

The hole transport region may include the second compound as described above.

In various embodiments, the hole transport region may include an emission auxiliary layer. The emission auxiliary layer may directly contact the emission layer.

In various embodiments, the hole transport region may include a hole injection layer and a hole transport layer, which are stacked in this stated order on the first electrode 110, a hole injection layer and an emission auxiliary layer, which are stacked in this stated order on the first electrode 110, or a hole injection layer, a hole transport layer, and an emission auxiliary layer, which are stacked in this stated order on the first electrode 110.

When the hole transport region includes an emission auxiliary layer, the emission auxiliary layer may include the second compound.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (Pani/DBSA), PEDOT/PSS (poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate)), polyaniline/camphor sulfonic acid (Pani/CSA), polyaniline/poly(4-styrenesulfonate) (Pani/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

L₂₀₁to L₂₀₄may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

L₂₀₅may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀alkylene group, a substituted or unsubstituted C₂-C₂₀alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer selected from 0 to 3,

xa5 may be an integer selected from 1 to 10, and

R₂₀₁to R₂₀₄and Q₂₀₁may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁and R₂₀₂may be optionally connected to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R₂₀₃and R₂₀₄may be optionally connected to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In various embodiments, in Formulae 201 and 202,

L₂₀₁to L₂₀₅may each independently be selected from

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁to Q₃₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In various embodiments, xa5 may be 1, 2, 3, or 4.

In various embodiments, R₂₀₁to R₂₀₄and Q₂₀₁may each independently be selected from

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁to Q₃₃are the same as described above.

In various embodiments, at least one selected from R₂₀₁to R₂₀₃in Formula 201 may each independently be selected from

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group.

In various embodiments, in Formula 202, i) R₂₀₁and R₂₀₂may be connected to each other via a single bond, and/or ii) R₂₀₃and R₂₀₄may be connected to each other via a single bond.

In various embodiments, at least one selected from R₂₀₁to R₂₀₄in Formula 202 may be selected from

a carbazolyl group; and

a carbazolyl group substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group.

The compound represented by Formula 201 may be represented by Formula 201A:

For example, the compound represented by Formula 201 may be represented by Formula 201A(1):

In various embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1:

In various embodiments, the compound represented by Formula 202 may be represented by Formula 202A:

In various embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

L₂₀₁to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂to R₂₀₄are the same as described above,

R₂₁₁and R₂₁₂are the same as described above in connection with R₂₀₃, and

R₂₁₃to R₂₁₇may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

In an implementation, the hole transport region may include at least one compound selected from Compounds HT1 to HT39.

A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one selected from a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,000 Å, and the thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may help increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may include those materials as described above.

[p-dopant]

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, e.g., a p-dopant.

A doping concentration of the p-dopant may be in a range of about 0.1 wt % to about 20 wt %, for example, about 0.5 wt % to about 10 wt %.

In various embodiments, a lowest unoccupied molecular orbital (LUMO) of the p-dopant may be about −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound.

For example, the p-dopant may include at least one selected from

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as a tungsten oxide or a molybdenum oxide;

1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221 below.

In Formula 221,

R₂₂₁to R₂₂₃may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, provided that at least one selected from R₂₂₁to R₂₂₃has at least one substituent selected from a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀alkyl group substituted with —F, a C₁-C₂₀alkyl group substituted with —Cl, a C₁-C₂₀alkyl group substituted with —Br, and a C₁-C₂₀alkyl group substituted with —I.

[Emission Layer in Organic Layer 150]

When the organic light-emitting device 10 is a full color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, or a blue emission layer, according to a sub-pixel. In various embodiments, the emission layer may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other. In various embodiments, the emission layer may include two or more materials selected from a red-light emission material, a green-light emission material, and a blue-light emission material, in which the two or more materials are mixed with each other in a single layer to emit white light.

In various embodiments, the emission layer of the organic light-emitting device 10 may be a first-color-light emission layer,

the organic light-emitting device 10 may further include i) at least one second-color-light emission layer or ii) at least one second-color-light emission layer and at least one third-color-light emission layer, between the first electrode 110 and the second electrode 190,

a maximum emission wavelength of the first-color-light emission layer, a maximum emission wavelength of the second-color-light emission layer, and a maximum emission wavelength of the third-color-light emission layer are identical to or different from each other, and

the organic light-emitting device 10 may emit mixed light including first-color-light and second-color-light, or mixed light including first-color-light, second-color-light, and third-color-light.

For example, the maximum emission wavelength of the first-color-light emission layer is different from a maximum emission wavelength of the second-color-light emission layer, and the mixed light including first-color-light and second-color-light may be white light.

In various embodiments, the maximum emission wavelength of the first-color-light emission layer, the maximum emission wavelength of the second-color-light emission layer, and the maximum emission wavelength of the third-color-light emission layer may be different from one another, and the mixed light including first-color-light, second-color-light, and third-color-light may be white light.

The emission layer may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant.

An amount of the dopant in the emission layer may be, in general, in a range of about 0.01 to about 15 parts by weight based on 100 parts by weight of the host.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

[Host in Emission Layer]

The emission layer may include the first compound according to an embodiment as a host. For example, the first compound is the same as described above.

In an implementation, the emission layer may include a first host and a second host, and the first host may include the first compound.

In an implementation, the second host may be selected from compounds described above as an example of the first compound.

In an implementation, the second host may be selected from 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), and 1,3,5-tri(carbazol-9-yl)benzene (TCP).

A weight ratio of the first host to the second host in the emission layer may be, for example, about 90:10 to about 10:90, for example, about 80:20 to about 20:80, or for example, about 50:50.

[Phosphorescent Dopant Included in Emission Layer in Organic Layer 150]

The phosphorescent dopant may include an organometallic complex represented by Formula 401 below, in which L₄₀₁may be selected from ligands represented by Formula 402.

wherein, in Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm),

xc1 may be 1, 2, or 3, wherein when xc1 is two or more, two or more L₄₀₁(s) may be identical to or different from each other,

L₄₀₂may be an organic ligand, and xc2 may be an integer selected from 0 to 4, wherein when xc2 is two or more, two or more L₄₀₂(s) may be identical to or different from each other,

X₄₀₁to X₄₀₄may each independently be nitrogen or carbon,

X₄₀₁and X₄₀₃may be connected to each other via a single bond or a double bond, and X₄₀₂and X₄₀₄may be connected to each other via a single bond or a double bond,

A₄₀₁and A₄₀₂may each independently be a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group,

X₄₀₅may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′ wherein Q₄₁₁and Q₄₁₂may each independently be hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆may be a single bond, O, or S,

R₄₀₁and R₄₀₂may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, —CD₃, —CF₃, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀alkyl group, a substituted or unsubstituted C₁-C₂₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁to Q₄₀₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a C₆-C₂₀aryl group, and a C₁-C₂₀heteroaryl group,

xc11 and xc12 may each independently be an integer selected from 0 to 10, and

* and *′ in Formula 402 indicate a binding site to M in Formula 401.

In various embodiments, A₄₀₁and A₄₀₂in Formula 402 may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzoimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In various embodiments, in Formula 402, i) X₄₀₁may be nitrogen, X₄₀₂may be carbon, or ii) both X₄₀₁and X₄₀₂may be nitrogen.

In various embodiments, R₄₀₁and R₄₀₂in Formula 402 may each independently be selected from

a C₁-C₂₀alkyl group and a C₁-C₂₀alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, and a norbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂),

wherein Q₄₀₁to Q₄₀₃may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, and a naphthyl group.

In various embodiments, when xc1 in Formula 401 is two or more, two A₄₀₁(s) selected from two or more L₄₀₁(s) may be optionally connected to each other via a linking group X₄₀₇, or two A₄₀₂(s) may be optionally connected to each other via a linking group X₄₀₈(see Compounds PD1 to PD4 and PD7 below). X₄₀₇and X₄₀₈may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)═C(Q₄₁₄)-*′ (wherein Q₄₁₃and Q₄₁₄may each independently be hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group).

L₄₀₂in Formula 401 may be a suitable monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂may be selected from a halogen, a diketone (for example, an acetylacetonate), a carboxylic acid (for example, a picolinate), —C(═O), an isonitrile, —CN, and phosphorus (for example, a phosphine or a phosphite).

In various embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25.

[Fluorescent Dopant in Emission Layer]

The fluorescent dopant may include an arylamine compound or a styrylamine compound.

In various embodiments, the fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

Ar₅₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

L₅₀₁to L₅₀₃may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer selected from 0 to 3,

R₅₀₁and R₅₀₂may each independently be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and

xd4 may be an integer selected from 1 to 6.

In various embodiments, Ar₅₀₁in Formula 501 may be selected from

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group; and

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, L₅₀₁to L₅₀₃in Formula 501 may each independently be selected from

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

In various embodiments, R₅₀₁and R₅₀₂in Formula 501 may each independently be selected from

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

In various embodiments, xd4 in Formula 501 may be two.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD22:

In various embodiments, the fluorescent dopant may be selected from compounds illustrated below.

[Electron Transport Region in Organic Layer 150]

The electron transport region may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron transport region may include at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer.

For example, the electron transport region may have a structure of electron transport layer/electron injection layer, a structure of hole blocking layer/electron transport layer/electron injection layer, a structure of electron control layer/electron transport layer/electron injection layer, or a structure of buffer layer/electron transport layer/electron injection layer, wherein, in each of these structures, constituting layers are sequentially stacked in this stated order from an emission layer.

The electron transport region may include the second compound according to an embodiment as described above.

In various embodiments, the electron transport region may include a buffer layer, and the buffer layer may directly contact the emission layer, and the buffer layer may include the second compound according to an embodiment as described above.

In various embodiments, the electron transport region may include a buffer layer, an electron transport layer, and an electron injection layer, which are stacked in this stated order on the emission layer, and the buffer layer may include the second compound as described above.

The electron transport region (e.g., a hole blocking layer, an electron control layer, or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one nt electron-depleted nitrogen-containing ring.

The “π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀heterocyclic group having at least one *—N═*′ moiety as a ring-forming moiety.

For example, the “π electron-depleted nitrogen-containing ring” may be i) a 5-membered to 7-membered hetero monocyclic group having at least one *—N═*′ moiety, ii) a heteropoly cyclic group in which two or more 5-membered to 7-membered hetero monocyclic groups each having at least one *—N═*′ moiety are condensed with each other, or iii) a heteropoly cyclic group in which at least one selected from 5-membered to 7-membered hetero monocyclic groups, each having at least one *—N═*′ moiety, is condensed with at least one C₅-C₆₀carbocyclic group.

Examples of the it electron-depleted nitrogen-containing ring are an imidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, an isoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, an indazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, a phthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline, a phenanthridine, an acridine, a phenanthroline, a phenazine, a benzoimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, a triazole, a tetrazole, an oxadiazole, a triazine, thiadiazol, an imidazopyridine, an imidazopyrimidine, and an azacarbazole.

For example, the electron transport region may include a compound represented by Formula 601:
[Ar₆₀₁]_xe11-[(L₆₀₁)_xe1-R₆₀₁]_xe21. <Formula 601>

In Formula 601,

Ar₆₀₁may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xe1 may be an integer selected from 0 to 5,

R₆₀₁may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁to Q₆₀₃may each independently be a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, and

xe₂₁may be an integer selected from 1 to 5.

In various embodiments, at least one selected from Ar₆₀₁(s) in the number of xe11 and/or at least one selected from R₆₀₁(s) in the number of xe21 may include the π electron-depleted nitrogen-containing ring.

In various embodiments, ring Ar₆₀₁in Formula 601 may be selected from

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzoimidazole group, an iso-benzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazol group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzoimidazole group, an iso-benzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazol group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

When xe11 in Formula 601 is two or more, two or more Ar₆₀₁(s) may be linked to each other via a single bond.

In various embodiments, Ar₆₀₁in Formula 601 may be an anthracene group.

In various embodiments, a compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1,

X₆₁₄may be N or C(R₆₁₄), X₆₁₅may be N or C(R₆₁₅), X₆₁₆may be N or C(R₆₁₆), and at least one selected from X₆₁₄to X₆₁₆may be N,

L₆₁₁to L₆₁₃may each independently be substantially the same as described in connection with L₆₀₁,

xe611 to xe613 may each independently be substantially the same as described in connection with xe1,

R₆₁₁to R₆₁₃may each independently be substantially the same as described in connection with R₆₀₁,

R₆₁₄to R₆₁₆may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In various embodiments, L₆₀₁and L₆₁₁to L₆₁₃in Formulae 601 and 601-1 may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group.

In various embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

In various embodiments, R₆₀₁and R₆₁₁to R₆₁₃in Formulae 601 and 601-1 may each independently be selected from

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁and Q₆₀₂are substantially the same as described above.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36.

In various embodiments, the electron transport region may include at least one selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-dphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and NTAZ.

The thickness of the buffer layer, the hole blocking layer, or the electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within these ranges, the electron blocking layer may have excellent electron blocking characteristics or electron control characteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.

The electron transport region (e.g., the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from an alkaline metal complex and an alkaline earth-metal complex. The alkaline metal complex may include a metal ion selected from an Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkaline metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenylan oxazole, a hydroxy phenylthiazole, a hydroxy diphenylan oxadiazole, a hydroxy diphenylthiadiazol, a hydroxy phenylpyridine, a hydroxy phenylbenzoimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2.

The electron transport region may include an electron injection layer that facilitates injection of electrons from the second electrode 190. The electron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structure including a single layer including a single material, ii) a single-layered structure including a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron injection layer may include an alkaline metal, an alkaline earth metal, a rare-earth metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or any combinations thereof.

In various embodiments, the electron injection layer may include Li, Na, K, Rb, Cs, Mg, Ca, Er, Tm, Yb, or any combination thereof.

The alkaline metal may be selected from Li, Na, K, Rb, and Cs. In various embodiments, the alkaline metal may be Li, Na, or Cs. In various embodiments, the alkaline metal may be Li or Cs.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare-earth metal may be selected from Sc, Y, Ce, Yb, Gd, and Tb.

The alkaline metal compound, the alkaline earth-metal compound, and the rare-earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, or iodines) of the alkaline metal, the alkaline earth-metal and the rare-earth metal.

The alkaline metal compound may be selected from alkaline metal oxides, such as Li₂O, Cs₂O, or K₂O, and alkaline metal halides, such as LiF, NaF, CsF, KF, LiI, NaI, CsI, RbI, or KI. In various embodiments, the alkaline metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI.

The alkaline earth-metal compound may be selected from alkaline earth-metal compounds, such as BaO, SrO, CaO, Ba_xSr_1-xO (0<x<1), or Ba_xCa_1-xO (0<x<1). In various embodiments, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO.

The rare-earth metal compound may be selected from YbF₃, ScF₃, ScO₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In various embodiments, the rare-earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃.

The alkaline metal complex, the alkaline earth-metal complex, and the rare-earth metal complex may include an ion of alkaline metal, an alkaline earth-metal, and a rare-earth metal as described above, and a ligand coordinated with a metal ion of the alkaline metal complex, the alkaline earth-metal complex, and the rare-earth metal complex may each independently be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenylan oxazole, a hydroxy phenylthiazole, a hydroxy diphenylan oxadiazole, a hydroxy diphenylthiadiazol, a hydroxy a phenylpyridine, a hydroxy phenylbenzoimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene.

The electron injection layer may consist of an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or any combinations thereof, as described above. In various embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, alkaline metal, alkaline earth metal, rare-earth-metal, alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or any combinations thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage.

At least one layer selected from the electron transport layer and the electron injection layer may include an alkaline metal, an alkaline earth metal, a rare-earth-metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or any combinations thereof.

[Second Electrode 190]

The second electrode 190 may be disposed on the organic layer 150 having such a structure. The second electrode 190 may be a cathode that is an electron injection electrode, and in this regard, a material for forming the second electrode 190 may be a material having a low work function, and such a material may be metal, alloy, an electrically conductive compound, or a combination thereof.

The second electrode 190 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO. The second electrode 190 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or a multi-layered structure including two or more layers.

[Description of FIGS. 2 to 5 ]

An organic light-emitting device 20 of FIG. 2 may include a first capping layer 210, a first electrode 110, an organic layer 150, and a second electrode 190 which are sequentially stacked in this stated order, an organic light-emitting device 30 of FIG. 3 may include a first electrode 110, an organic layer 150, a second electrode 190, and a second capping layer 220 which are sequentially stacked in this stated order, and an organic light-emitting device 40 of FIG. 4 may include a first capping layer 210, a first electrode 110, an organic layer 150, a second electrode 190, and a second capping layer 220.

Regarding FIGS. 2 to 4 , the first electrode 110, the organic layer 150, and the second electrode 190 may be understood by referring to the description presented in connection with FIG. 1 .

In the organic layer 150 of each of the organic light-emitting

devices

20 and 40, light generated in an emission layer may pass through the first electrode 110, which is a semi-transmissive electrode or a transmissive electrode, and the first capping layer 210 toward the outside, and in the organic layer 150 of each of the organic light-emitting

devices

30 and 40, light generated in an emission layer may pass through the second electrode 190, which is a semi-transmissive electrode or a transmissive electrode, and the second capping layer 220 toward the outside.

The first capping layer 210 and the second capping layer 220 may increase external luminescent efficiency according to the principle of constructive interference.

The first capping layer 210 and the second capping layer 220 may each independently be a capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.

At least one selected from the first capping layer 210 and the second capping layer 220 may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphine derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkaline metal complexes, and alkaline earth-based complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I. In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include an amine-based compound.

In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include the compound represented by Formula 201 or the compound represented by Formula 202.

In various embodiments, at least one selected from the first capping layer 210 and the second capping layer 220 may each independently include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5.

FIG. 5 illustrates a schematic view of an organic light-emitting device 11 according to an embodiment. The organic light-emitting device 11 may include a first electrode 110, a hole transport layer 151, an emission auxiliary layer 153, an emission layer 155, a buffer layer 156, an electron transport layer 157, an electron injection layer 159, and a second electrode 190, which are sequentially stacked in this stated order.

Respective layers constituting the organic light-emitting device 11 of FIG. 5 may be understood by referring to corresponding descriptions above.

Hereinbefore, the organic light-emitting device according to an embodiment has been described in connection with FIGS. 1 to 5 .

Layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region may be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, langmuir-blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When the respective layers of the hole transport region, the emission layer, and the respective layers of the electron transport region are formed by deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., at a vacuum degree of about 10⁻⁸torr to about 10⁻³torr, and at a deposition rate of about 0.01 Å/sec to about 100 Å/sec by taking into account a material for forming a layer to be deposited and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to about 200° C. by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.

[General Definition of Substituents]

The term “C₁-C₆₀alkyl group,” as used herein, refers to a linear or branched aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀alkylene group,” as used herein, refers to a divalent group having the same structure as the C₁-C₆₀alkyl group.

The term “C₂-C₆₀alkenyl group,” as used herein, refers to a hydrocarbon group formed by substituting at least one carbon-carbon double bond in the middle or at the terminal of the C₂-C₆₀alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkylene group,” as used herein, refers to a divalent group having the same structure as the C₂-C₆₀alkyl group.

The term “C₂-C₆₀alkynyl group,” as used herein, refers to a hydrocarbon group formed by substituting at least one carbon trip bond in the middle or at the terminal of the C₂-C₆₀alkyl group, and non-limiting examples thereof include an ethynyl group and a propynyl group. The term “C₂-C₆₀alkylene group,” as used herein, refers to a divalent group having the same structure as the C₂-C₆₀alkyl group.

The term “C₁-C₆₀alkoxy group,” as used herein, refers to a monovalent group represented by —OA₁₀₁(wherein A₁₀₁is the C₁-C₆₀alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀cycloalkyl group,” as used herein, refers to a monovalent hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀cycloalkylene group,” as used herein, refers to a divalent group having the same structure as the C₃-C₁₀cycloalkyl group.

The term “C₁-C₁₀heterocycloalkyl group,” as used herein, refers to a monovalent saturated monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀heterocycloalkylene group,” as used herein, refers to a divalent group having the same structure as the C₁-C₁₀heterocycloalkyl group.

The term “C₃-C₁₀cycloalkenyl group,” as used herein, refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one double bond in the ring thereof and does not have aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀cycloalkenylene group,” as used herein, refers to a divalent group having the same structure as the C₃-C₁₀cycloalkenyl group.

The term “C₁-C₁₀heterocycloalkenyl group,” as used herein, refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one double bond in its ring. Non-limiting examples of the C₁-C₁₀heterocycloalkenyl group are a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀heterocycloalkenylene group,” as used herein, refers to a divalent group having the same structure as the C₁-C₁₀heterocycloalkenyl group.

The term “C₆-C₆₀aryl group,” as used herein, refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀arylene group,” as used herein, refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀aryl group and the C₆-C₆₀arylene group each include two or more rings, the rings may be fused to each other.

The term “C₁-C₆₀heteroaryl group,” as used herein, refers to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. The term “C₁-C₆₀heteroarylene group,” as used herein, refers to a divalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀heteroarylene group each include two or more rings, the rings may be fused to each other.

The term “C₆-C₆₀aryloxy group,” as used herein, refers to —OA₁₀₂(wherein A₁₀₂is the C₆-C₆₀aryl group), and a C₆-C₆₀arylthio group used herein indicates —SA₁₀₃(wherein A₁₀₃is the C₆-C₆₀aryl group).

The term “monovalent non-aromatic condensed polycyclic group,” as used herein, refers to a monovalent group (for example, having 8 to 60 carbon atoms) that has two or more rings condensed with each other, only carbon atoms as a ring-forming atom, and non-aromaticity in the entire molecular structure. A detailed example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group,” used herein, refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” as used herein, refers to a monovalent group (for example, having 1 to 60 carbon atoms) that has two or more rings condensed to each other, has at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms, as a ring-forming atom, and has non-aromaticity in the entire molecular structure. An example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group,” used herein, refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₆₀carbocyclic group,” as used herein, refers to a monocyclic or polycyclic group having 5 to 60 carbon atoms in which a ring-forming atom is a carbon atom only. The term “C₅-C₆₀carbocyclic group,” as used herein refers to an aromatic carbocyclic group or a non-aromatic carbocyclic group. The term “C₅-C₆₀carbocyclic group,” as used herein, refers to a ring, such as a benzene, a monovalent group, such as a phenyl group, or a divalent group, such as a phenylene group. In various embodiments, depending on the number of substituents connected to the C₅-C₆₀carbocyclic group, the C₅-C₆₀carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀heterocyclic group,” as used herein, refers to a group having the same structure as the C₁-C₆₀carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon (the number of carbon atoms may be in a range of 1 to 60).

At least one substituent selected from the substituted C₅-C₆₀carbocyclic group, the substituted C₁-C₆₀heterocyclic group, the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀alkoxy group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀alkoxy group;

a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

The term “Ph”, as used herein, may refer to a phenyl group; the term “Me”, as used herein, may refer to a methyl group; the term “Et”, as used herein, may refer to an ethyl group; the terms “ter-Bu” or “But”, as used herein, may refer to a tert-butyl group; and the term “OMe,” as used herein refers to a methoxy group.

The “biphenyl group” used therein refers to “a phenyl group substituted with a phenyl group.” The “biphenyl group” belongs to “a substituted phenyl group” having “a C₆-C₆₀aryl group” as a substituent.

The “terphenyl group” used herein refers to “a phenyl group substituted with a biphenyl group.” The “terphenyl group” belongs to “a substituted phenyl group” having “a C₆-C₆₀aryl group substituted with a C₆-C₆₀aryl group.”

Symbols * and *′ used herein, unless defined otherwise, refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to embodiments and an organic light-emitting device according to embodiments will be described in detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples means that a molar equivalent of A was identical to a molar equivalent of B.

EXAMPLE

The following Examples and Comparative Examples are provided in order to highlight characteristics of one or more embodiments, but it will be understood that the Examples and Comparative Examples are not to be construed as limiting the scope of the embodiments, nor are the Comparative Examples to be construed as being outside the scope of the embodiments. Further, it will be understood that the embodiments are not limited to the particular details described in the Examples and Comparative Examples.

Example 1-1: Manufacture of Red Organic Light-Emitting Device

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning), having a thickness of 1,200 Å and sheet resistance of 15 Ω/cm², to a size of 50 mm×50 mm×0.5 mm, ultrasonically cleaning the ITO glass substrate using isopropyl alcohol and pure water each for 15 minutes, and then, exposing the ITO glass substrate to UV light irradiation for 30 minutes and ozone to clean the ITO glass substrate. Then, the ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum-deposited on the ITO glass substrate (anode) to a thickness of 700 Å to form a hole transport layer. Then, TCTA was vacuum deposited on the hole transport layer to a thickness of 100 Å to form an emission auxiliary layer.

Compound 1-1 (as a host) and PD11 (as a dopant) were co-deposited on the emission auxiliary layer at a weight ratio of 98:2 to form an emission layer having a thickness of 300 Å.

Compound 2-9 was deposited on the emission layer to form a buffer layer having a thickness of 100 Å, and then, Alq₃was vacuum deposited on the buffer layer to form an electron transport layer having a thickness of 200 Å. LiF was deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å.

Al was deposited on the electron injection layer to form a cathode having a thickness of 2,000 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 1-2 to 1-10 and Comparative Examples 1-1 to 1-3

Organic light-emitting devices were manufactured in the same manner as in Example 1-1, except that compounds shown in Table 5 were used in forming an emission layer and a buffer layer.

Evaluation Example 1

The driving voltage and efficiency of the organic light-emitting devices of Examples 1-1 to 1-10 and Comparative Examples 1-1 to 1-3 were evaluated at 5 mA/cm²by using a Keithley SMU 236 meter. Results thereof are shown in Table 5.

TABLE 5

Emission layer		Driving	Efficiency
(host)	Buffer layer	voltage (V)	(cd/A)

Example	Compound	Compound	5.3	23.9
1-1	1-1	2-9
Example	Compound	Compound	5.4	24.5
1-2	1-6	2-48
Example	Compound	Compound	5.2	23.7
1-3	1-124	2-147a
Example	Compound	Compound	5.3	24.1
1-4	1-97	2-143a
Example	Compound	Compound	5.5	23.8
1-5	1-41	2-48
Example	Compound	Compound	5.5	24.5
1-6	1-19	2-93
Example	Compound	Compound	5.3	25.3
1-7	1-57	2-153
Example	Compound	Compound	5.3	25.1
1-8	1-64	2-165
Example	Compound	Compound	5.4	24.0
1-9	1-126	2-189
Example	Compound	Compound	5.2	24.7
1-10	1-137	2-211
Comparative	CBP	Compound	5.9	22.3
Example		2-9
1-1
Comparative	Compound	BAlq	5.8	22.7
Example	1-1
1-2
Comparative	CBP	BAlq	6.2	21.6
Example
1-3

Referring to Table 5, it may be seen that the organic light-emitting devices of Examples 1-1 to 1-10 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 1-1 to 1-3.

Example 2-1: Manufacture of Green (Phosphorescent) Organic Light-Emitting Device

An anode was prepared by cutting an ITO glass substrate (manufactured by Corning), having a thickness of 1,200 Å and sheet resistance of 15 Ω/cm², to a size of 50 mm×50 mm×0.5 mm, ultrasonically cleaning the ITO glass substrate using isopropyl alcohol and pure water each for 15 minutes, and then, exposing to irradiation of UV light for 30 minutes and ozone to clean. Then, the ITO glass substrate was loaded into a vacuum deposition apparatus.

m-MTDATA was vacuum deposited on the ITO glass substrate (anode) to a thickness of 700 Å to form a hole transport layer. Then, TCTA was vacuum deposited on the hole transport layer to a thickness of 100 Å to form an emission auxiliary layer.

Compound 1-1 (as a host) and PD13 (as a dopant) were co-deposited on the emission auxiliary layer at a weight ratio of 90:10 to form an emission layer having a thickness of 300 Å.

Examples 2-2 to 2-5 and Comparative Examples 2-1 to 2-3

Organic light-emitting devices were manufactured in the same manner as in Example 2-1, except that compounds shown in Table 6 were used in forming an emission layer and a buffer layer.

Example 2-6

An organic light-emitting device was manufactured in the same manner as in Example 2-1, except that Compound 1-1 (as a first host), CBP (as a second host), and PD13 (as a dopant) were co-deposited at a weight ratio of 50:50:10 in forming an emission layer.

Examples 2-7 to 2-10

Organic light-emitting devices were manufactured in the same manner as in Example 2-6, except that compounds shown in Table 7 were used in forming an emission layer and a buffer layer.

Example 2-11: Manufacture of Green (Fluorescent) Organic Light-Emitting Device

m-MTDATA was vacuum deposited on the ITO glass substrate (anode) to a thickness of 700 Å to form a hole transport layer. Then, NPB was vacuum deposited on the hole transport layer to a thickness of 100 Å to form an emission auxiliary layer.

Compound 1-166 (as a host) and FD19 (as a dopant) were co-deposited on the emission auxiliary layer at a weight ratio of 95:5 to form an emission layer having a thickness of 300 Å.

Examples 2-12 to 2-15 and Comparative Examples 2-4 to 2-6

Organic light-emitting devices were manufactured in the same manner as in Example 2-11, except that compounds shown in Table 6 were used in forming an emission layer and a buffer layer.

Evaluation Example 2

The driving voltage and efficiency of the organic light-emitting devices of Examples 2-1 to 2-15 and Comparative Examples 2-1 to 2-6 were evaluated at 5 mA/cm²(phosphorescence) and 10 mA/cm²(fluorescence) by using a Keithley SMU 236 meter. Results thereof are shown in Tables 6 and 7.

TABLE 6

	Emission
Emission layer	layer	Buffer	Weight ratio	Driving	Efficiency
(host)	(dopant)	layer	(host:dopant)	voltage (V)	(cd/A)

Example 2-1	Compound	PD13	Compound	90:10	5.5	41.5
	1-1		2-9
Example 2-2	Compound	PD13	Compound	90:10	5.2	43.6
	1-20		2-48
Example 2-3	Compound	PD13	Compound	90:10	5.4	42.8
	1-46		2-136a
Example 2-4	Compound	PD13	Compound	90:10	5.4	43.1
	1-59		2-103
Example 2-5	Compound	PD13	Compound	90:10	5.3	42.6
	1-104		2-162
Comparative	CBP	PD13	Compound	90:10	5.9	38.7
Example 2-1			2-9
Comparative	Compound	PD13	BAlq	90:10	5.9	38.3
Example 2-2	1-1
Comparative	CBP	PD13	BAlq	90:10	6.1	36.1
Example 2-3
Example 2-11	Compound	FD19	Compound	95:5	4.5	19.1
	1-1		2-9
Example 2-12	Compound	FD19	Compound	95:5	4.7	19.9
	1-20		2-48
Example 2-13	Compound	FD19	Compound	95:5	4.4	20.1
	1-46		2-136a
Example 2-14	Compound	FD19	Compound	95:5	4.3	19.8
	1-59		2-103
Example 2-15	Compound	FD19	Compound	95:5	4.5	20.3
	1-104		2-162
Comparative	ADN	FD19	Compound	95:5	4.8	18.3
Example 2-4			2-9
Comparative	Compound	FD19	Alq₃	95:5	4.6	17.8
Example 2-5	1-166
Comparative	ADN	FD19	Alq₃	95:5	5.0	16.2
Example 2-6

TABLE 7

Emission			Weight ratio
layer	Emission		(first
(first host:second	layer	Buffer	host:second	Driving	Efficiency
host)	(dopant)	layer	host:dopant)	voltage (V)	(cd/A)

Example 2-6	Compound	PD13	Compound	50:50:10	5.5	41.1
	1-1:CPB		2-9
Example 2-7	Compound	PD13	Compound	50:50:10	5.3	42.3
	1-1:Compound		2-48
	1-39
Example 2-8	Compound	PD13	Compound	50:50:10	5.2	42.7
	1-20:Compound		2-136a
	1-41
Example 2-9	Compound	PD13	Compound	50:50:10	5.4	42.0
	1-113:Compound		2-103
	1-60
Example 2-10	Compound	PD13	Compound	50:50:10	5.3	43.2
	1-46:Compound		2-162
	1-16

Referring to Tables 6 and 7, it may be seen that the organic light-emitting devices of Examples 2-1 to 2-10 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 2-1 to 2-3, and the organic light-emitting devices of the Examples 2-11 to 2-15 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 2-4 to 2-6.

Example 3-1: Manufacture of Blue Organic Light-Emitting Device

Compound 1-166 (as a host) and FD1 (as a dopant) were co-deposited on the emission auxiliary layer at a weight ratio of 95:5 to form an emission layer having a thickness of 300 Å.

Examples 3-2 to 3-5 and Comparative Examples 3-1 to 3-3

Organic light-emitting devices were manufactured in the same manner as in Example 3-1, except that compounds shown in Table 8 were used in forming an emission layer and a buffer layer.

Example 3-6 to 3-10

Organic light-emitting devices were manufactured in the same manner as in Example 3-1, except that 1 wt % of F4-TCNQ was doped in forming a hole transport layer and that compounds shown in Table 8 were used in forming an emission layer and a buffer layer.

TABLE 8

Emission layer		Driving	Efficiency
(host)	Buffer layer	voltage (V)	(cd/A)

Example	Compound	Compound	4.5	5.1
3-1	1-166	2-9
Example	Compound	Compound	4.5	5.3
3-2	1-164	2-48
Example	Compound	Compound	4.6	5.0
3-3	1-178	2-136a
Example	Compound	Compound	4.4	4.9
3-4	1-164	2-103
Example	Compound	Compound	4.4	5.2
3-5	1-178	2-162
Example	Compound	Compound	4.2	5.2
3-6	1-165	2-131
Example	Compound	Compound	4.1	5.0
3-7	1-171	2-121a
Example	Compound	Compound	4.2	5.0
3-8	1-171	2-180
Example	Compound	Compound	4.2	5.2
3-9	1-176	2-13a
Example	Compound	Compound	4.3	5.1
3-10	1-176	2-242
Comparative	ADN	Compound	4.7	4.6
Example		2-9
3-1
Comparative	Compound	Alq₃	4.6	4.8
Example	1-166
3-2
Comparative	ADN	Alq₃	4.9	4.4
Example
3-3

Referring to Table 8, it may be seen that the organic light-emitting devices of Examples 3-1 to 3-10 had a low driving voltage and high efficiency, compared to those of the organic light-emitting devices of Comparative Examples 3-1 to 3-3.

According to one or more embodiments, an organic light-emitting device may have a low driving voltage and high efficiency.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

What is claimed is:

1. An organic light-emitting device, comprising:

a first electrode;

a second electrode facing the first electrode;

an emission layer between the first electrode and the second electrode;

a hole transport region between the first electrode and the emission layer; and

an electron transport region between the emission layer and the second electrode, wherein:

the emission layer includes a first compound,

at least one of the hole transport region and the electron transport region includes a second compound,

the first compound is represented by Formula 1A or 1B and the first compound is not Compound ST1, and

the second compound is represented by Formula 2A or 2B:

wherein, in Formulae 1A, 1B, 2A, and 2B,

rings A₁to A₃are each independently selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀heterocyclic group,

rings A₁to A₃are each condensed with a spiro-ring in Formulae 1A and 1B,

rings A₂₁, A₂₂, and A₂₃are each independently a C₅-C₆₀carbocyclic group or C₁-C₆₀heterocyclic group, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22], in which * is a bonding site to a neighboring atom,

T₁₁and T₁₂are each independently carbon or nitrogen, two or three T₁₁in Formula 2A are identical to or different from each other, T₁₃is N or C(R₂₇), T₁₄is N or C(R₂₈), two or three T₁₂in Formula 2A are identical to or different from each other, two T₁₁in Formula 2B are identical to or different from each other, two T₁₂in Formula 2B are identical to or different from each other, T₁₁and T₁₂are connected to each other via a single bond or a double bond,

three T₁₁and three T₁₂in Formula 2A are not all nitrogen and two T₁₁, two T₁₂,

T₁₃, and T₁₄in Formula 2B are not all nitrogen,

rings A₂₁, A₂₂, and A₂₃are each condensed with a 7-membered ring in Formulae 2A and 2B, while sharing T₁₁and T₁₂therewith,

X₁is a silicon (Si) atom or a carbon (C) atom,

Y₁is selected from a single bond, N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se,

Y₂is selected from a single bond, N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), Si(R₁₂)(R₁₄), O, S, and Se,

E₁and E₂are each independently a nitrogen (N) atom, or a carbon (C) atom substituted with *-(L₄)_a4-(R₄)_b4, in which * is a bonding site to a neighboring atom,

X₂₁is selected from O, S, Se, C(R₂₃)(R₂₄), Si(R₂₃)(R₂₄), and N[(L₂₁)_a21-(R₂₁)_b21],

L₁to L₄, L₁₁, L₁₂, L₂₁, and L₂₂are each independently selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group, provided that L₁to L₄are each independently not a substituted or unsubstituted triazinylene group,

a1 to a4, a11, a12, a21, and a22 are each independently an integer of 0 to 5,

R₁₁to R₁₄, R₂₁to R₂₄, R₂₇, and R₂₈are each independently selected from hydrogen, deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

R₁to R₄are each independently selected from hydrogen, deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀alkynyl group, a substituted or unsubstituted C₁-C₆₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

provided that when a1 to a4 are each independently 0, respective R₁to R₄are each independently not a substituted triazinyl group,

R₁₁and R₁₃are separate or are connected to each other to form a saturated or unsaturated ring,

R₁₂and R₁₄are separate or are connected to each other to form a saturated or unsaturated ring,

b1 to b4, b11, b12, b21, and b22 are each independently an integer of 1 to 3,

c1 and c2 are each independently an integer of 0 to 8, and c3 and c4 are each independently an integer of 0 to 4, and

at least one substituent of the substituted C₃-C₁₀cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀heterocycloalkenylene group, the substituted C₆-C₆₀arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀alkyl group, the substituted C₂-C₆₀alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀alkoxy group, the substituted C₃-C₁₀cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀aryl group, the substituted C₆-C₆₀aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from:

wherein Q₁to Q₃, Q₁₁to Q₁₃, Q₂₁to Q₂₃, and Q₃₁to Q₃₃are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀aryl group substituted with a C₁-C₆₀alkyl group, a C₆-C₆₀aryl group substituted with a C₆-C₆₀aryl group, a terphenyl group, a C₁-C₆₀heteroaryl group, a C₁-C₆₀heteroaryl group substituted with a C₁-C₆₀alkyl group, a C₁-C₆₀heteroaryl group substituted with a C₆-C₆₀aryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group.

2. The organic light-emitting device as claimed in claim 1, wherein rings A₁to A₃in Formulae 1A and 1B are each independently selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an indene group, an indenopyridine group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyrrole group, an imidazole group, a quinoline group, an isoquinoline group, a quinazoline group, a phenanthroline group, a phenanthridine group, a furan group, a thiophene group, an indole group, an indolocarbazole group, a benzofuran group, a benzofurocarbazole group, a benzofuropyrimidine group, a benzothiophene group, a benzoxazole group, a benzothiazole group, a benzoimidazole group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a pyridoindole group, a dipyridofuran group, a dipyridothiophene group, a pyrimidobenzofuran group, a dipyridopyrrole group, and a pyrimidobenzothiophene group.

3. The organic light-emitting device as claimed in claim 1, wherein rings A₂₁, A₂₂, and A₂₃in Formulae 2A and 2B are each independently selected from a benzene group, a naphthalene group, an anthracene group, an indene group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a quinoline group, an isoquinoline group, a pyrrole group, a pyrazole group, an imidazole group, an oxazole group, a thiazole group, a cyclopentadiene group, a silole group, a selenophene group, a furan group, a thiophene group, an indole group, a benzoimidazole group, a benzoxazole group, a benzothiazole group, an indene group, a benzosilole group, a benzoselenophene group, a benzofuran group, a benzothiophene group, a carbazole group, a fluorene group, a dibenzosilole group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene group, a pyrrolopyridine group, a cyclopentapyridine group, a silolopyridine group, a selenophenopyridine group, a furopyridine group, a thienopyridine group, a pyrrolopyrimidine group, a cyclopentapyrimidine group, a silolopyrimidine group, a selenophenopyrimidine group, a furopyrimidine group, a thienopyrimidine group, a pyrrolopyrazine group, a cyclopentapyrazine group, a silolopyrazine group, a selenophenopyrazine group, a furopyrazine group, a thienopyrazine group, a naphthopyrrole group, a cyclopentanaphthalene group, a naphthosilole group, a naphthoselenothiophene group, a naphthofuran group, a naphthothiophene group, a pyrroloquinoline group, a cyclopentaquinoline group, a siloloquinoline group, a selenophenoquinoline group, a furoquinoline group, a thienoquinoline group, a pyrroloisoquinoline group, a cyclopentaisoquinoline group, a siloloisoquinoline group, a selenophenoisoquinoline group, a furoisoquinoline group, a thienoisoquinoline group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene group, an indenoquinoline group, an indenoisoquinoline group, an indenoquinoxaline group, a phenanthroline group, and a naphthoindole group, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22], in which * is a bonding site to a neighboring atom.

4. The organic light-emitting device as claimed in claim 1, wherein:

rings A₂₁A₂₂, and A₂₃in Formulae 2A and 2B are each independently a group represented by one of the following Formulae 2-1 to 2-36, each substituted with at least one *-[(L₂₂)_a22-(R₂₂)_b22)], in which * is a bonding site to a neighboring atom,

wherein, in Formulae 2-1 to 2-36,

T₁₁and T₁₂are defined the same as those of Formulae 2A and 2B,

X₂₂and X₂₃are each independently selected from O, S, Se, a carbon-containing moiety, a nitrogen-containing moiety, and a silicon-containing moiety, and

T₂₁to T₂₈are each independently selected from N and a carbon-containing moiety.

5. The organic light-emitting device as claimed in claim 1, wherein, in Formulae 1A and 1B:

Y₁and Y₂are both a single bond,

Y₁is a single bond and Y₂is selected from N[(L₁₂)_a12-(R₁₂)_b12], C(R₁₂)(R₁₄), Si(R₁₂)(R₁₄), O, S, and Se, or

Y₁is selected from N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se, and Y₂is a single bond.

6. The organic light-emitting device as claimed in claim 1, wherein X₂₁in Formulae 2A and 2B is N[(L₂₁)_a21-(R₂₁)_b21].

7. The organic light-emitting device as claimed in claim 4, wherein:

X₂₁in Formulae 2A and 2B is O, S, Se, C(R₂₃)(R₂₄), or Si(R₂₃)(R₂₄), and

at least one of rings A₂₁, A₂₂, and A₂₃in Formula 2A and at least one of rings A₂₁and A₂₃in Formula 2B are each independently a group represented by one of Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36, in which X₂₂or X₂₃in Formulae 2-1 to 2-3, 2-10 to 2-27, and 2-33 to 2-36 is N-[(L₂₂)_a22-(R₂₂)_b22].

8. The organic light-emitting device as claimed in claim 1, wherein, in Formulae 1A, 1B, 2A, and 2B, L₁₁, L₁₂, L₂₁, and L₂₂are each independently selected from:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a triazinylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

L₁to L₄are each independently selected from:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a guinolinylene group, an isoguinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a spiro-benzofluorene-fluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a pyrrolylene group, a thiophenylene group, a furanylene group, a silolylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a pyridinylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, an indolylene group, an isoindolylene group, an indazolylene group, a purinylene group, a quinolinylene group, an isoquinolinylene group, a benzoguinolinylene group, a phthalazinylene group, a naphthyridinylene group, a guinoxalinylene group, a guinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzoimidazolylene group, a benzofuranylene group, a benzothiophenylene group, a benzosilolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an oxadiazolylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a dibenzosilolylene group, a carbazolylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a thiadiazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, an oxazolopyridinylene group, a thiazolopyridinylene group, a benzonaphthyridinylene group, an azafluorenylene group, an azaspiro-bifluorenylene group, an azacarbazolylene group, an azadibenzofuranylene group, an azadibenzothiophenylene group, and an azadibenzosilolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁),

and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁to Q₃₃are each independently selected from:

9. The organic light-emitting device as claimed in claim 1, wherein, in Formulae 1A, 1B, 2A, and 2B, R₁₁to R₁₄, R₂₁to R₂₄, R₂₇, and R₂₈are each independently selected from:

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂); and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and

R₁to R₄are each independently selected from:

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, an azadibenzosilolyl group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂); and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a spiro-benzofluorene-fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolyl group, an indazolyl group, a purinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinol group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzoimidazolyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a dibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an oxazolopyridinyl group, a thiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenyl group, an azaspiro-bifluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group, an azadibenzothiophenyl group, and an azadibenzosilolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁to Q₃and Q₃₁to Q₃₃are each independently selected from:

10. The organic light-emitting device as claimed in claim 1, wherein the first compound is represented by one of the following Formulae 1-1 to 1-3:

wherein, in Formulae 1-1 to 1-3,

rings A₁to A₃, X₁, Y₁, E₁, E₂, L₁to L₄, a1 to a4, R₁to R₄, b1 to b4, c1, c2, c4, a11, R₁₁, R₁₃, and b11 are defined the same as those of Formulae 1A and 1B,

c2 is an integer of 0 to 6, and

Y₁is selected from N[(L₁₁)_a11-(R₁₁)_b11], C(R₁₁)(R₁₃), Si(R₁₁)(R₁₃), O, S, and Se.

11. The organic light-emitting device as claimed in claim 10, wherein, in Formulae 1-1 to 1-3:

ring A₁is selected from a benzene group, a naphthalene group, a pyridine group, a dibenzofuran group, and a pyrimidine group,

rings A₂and A₃are each independently selected from a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, an indene group, an indenopyridine group, a fluorene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyrrole group, an imidazole group, a quinoline group, an isoquinoline group, a quinazoline group, a phenanthroline group, a phenanthridine group, a furan group, a thiophene group, an indole group, an indolocarbazole group, a benzofuran group, a benzofurocarbazole group, a benzofuropyrimidine group, a benzothiophene group, a benzoxazole group, a benzothiazole group, a benzoimidazole group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a pyridoindole group, a dipyridofuran group, a dipyridothiophene group, a pyrimidobenzofuran group, a dipyridopyrrole group, and a pyrimidobenzothiophene group, and

R₁to R₄are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, a terphenyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂).

12. The organic light-emitting device as claimed in claim 1, wherein the emission layer includes a first host and a second host, the first host including the first compound.

13. The organic light-emitting device as claimed in claim 1, wherein:

the electron transport region includes a buffer layer,

the buffer layer directly contacts the emission layer, and

the buffer layer includes the second compound.

14. The organic light-emitting device as claimed in claim 1, wherein:

the emission layer includes a dopant, and

the dopant includes an organometallic complex.

15. The organic light-emitting device as claimed in claim 14, wherein the organometallic complex is represented by Formula 401, in which L₄₀₁is selected from a ligand represented by Formula 402,

M(L₄₀₁)_xc1(L₄₀₂)_xc2 <Formula 401>

wherein, in Formulae 401 and 402,

M is selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm),

xc1 is 1, 2, or 3, wherein when xc1 is 2 or 3, 2 or 3 L₄₀₁are identical to or different from each other,

L₄₀₂is an organic ligand, and xc2 is an integer of 0 to 4, wherein when xc2 is 2, 3, or 4, 2, 3, or 4 L₄₀₂are identical to or different from each other,

X₄₀₁to X₄₀₄are each independently nitrogen or carbon,

X₄₀₁and X₄₀₃are connected to each other via a single bond or a double bond,

and X₄₀₂and X₄₀₄are connected to each other via a single bond or a double bond,

A₄₀₁and A₄₀₂are each independently a C₅-C₆₀carbocyclic group or a C₁-C₆₀heterocyclic group,

X₄₀₅is a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′,

C(Q₄₁₁)═C(Q₄₁₂)-*′, *—C(Q₄₁₁)=*′, or *═C(Q₄₁₁)=*′, in which * is a bonding site to a neighboring atom, wherein Q₄₁₁and Q₄₁₂are each independently hydrogen, deuterium, a C₁-C₂₀alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆is a single bond, O, or S,

R₄₀₁and R₄₀₂are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, -CD₃, —CF₃, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀alkyl group, a substituted or unsubstituted C₁-C₂₀alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀arylthio group, a substituted or unsubstituted C₁-C₆₀heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁),

and —P(═O)(Q₄₀₁)(Q₄₀₂), wherein Q₄₀₁to Q₄₀₃are each independently selected from a C₁-C₁₀alkyl group, a C₁-C₁₀alkoxy group, a C₆-C₂₀aryl group, and a C₁-C₂₀heteroaryl group,

xc11 and xc12 are each independently an integer of 0 to 10, and

* and *′ in Formula 402 indicate a binding site to M in Formula 401.

16. The organic light-emitting device as claimed in claim 1, wherein:

the electron transport region includes a buffer layer, an electron transport layer, and an electron injection layer, and

at least one layer of the electron transport layer and the electron injection layer includes an alkaline metal, an alkaline earth metal, a rare-earth metal, an alkaline metal compound, an alkaline earth-metal compound, a rare-earth metal compound, an alkaline metal complex, an alkaline earth-metal complex, a rare-earth metal complex, or a combination thereof.

17. The organic light-emitting device as claimed in claim 1, wherein the hole transport region includes a p-dopant, and the p-dopant includes a cyano group-containing compound.

18. The organic light-emitting device as claimed in claim 1, wherein

the emission layer is a first-color-light emission layer,

the organic light-emitting device further includes at least one second-color-light emission layer or at least one second-color-light emission layer and at least one third-color-light emission layer, between the first electrode and the second electrode,

a maximum emission wavelength of the first-color-light emission layer, a maximum emission wavelength of the second-color-light emission layer, and a maximum emission wavelength of the third-color-light emission layer are identical to or different from one another, and

mixed light including first-color-light and second-color-light, or mixed light including first-color-light, second-color-light, and third-color-light is emitted.

19. The organic light-emitting device as claimed in claim 1, wherein the second compound is represented by Formula 2B.

20. The organic light-emitting device as claimed in claim 1, wherein the second compound is selected from the following compounds: